Chewing-gum stimulation did not reduce the absorbed dose to salivary glands during radioiodine treatment of thyroid cancer as inferred from pre-therapy 124I PET/CT imaging

SummaryAim: A theoretical dosimetry-based model was applied to estimate the lowest effective radioiodine activity for thyroid remnant ablation of low-risk differentiated thyroid cancer patients. Patients, methods: The model is based on the distribution of the absorbed (radiation) dose per administered radioiodine activity and the absorbed dose threshold of 300 Gy for thyroid remnants, the level believed to destroy most thyroid remnants. For this purpose, 124I PET/CT images of 49 thyroid-ectomised patients were retrospectively analysed to measure the distribution of the (average) absorbed doses to thyroid remnant per administered 131I activity. The fraction of thyroid remnants that received at least 300 Gy was determined for standard activities between 0.37 and 5.55 GBq. The lower activity was considered to be equally effective to that obtained with higher activity if the (absolute) fraction difference was below 5%. Results: A total of 62 thyroid remnants were included. The medians and ranges (in parentheses) for the absorbed dose per unit 131I activity were 359 Gy/GBq (34 to 1825 Gy/ GBq). The fractions of thyroid remnants receiving more than 300 Gy at different therapy activities (within parentheses) were 60% (1.11 GBq), 76% (1.85 GBq), 79% (2.22 GBq), and 81–82% for activities between 2.59 and 3.70 GBq. The therapy activity of 1.11 GBq is considerably less effective than that of 1.85 or 2.22 GBq; therapy activities were equally effective in the range between 2.22 to 3.70 GBq. Conclusion: On the basis of the model and the patients' data included, the lowest effective therapy activity appears to be approximately 2.2 GBq to ablate thyroid remnants. The results of this study may help to guide the design of prospective clinical studies.

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Clinical impact of 68Ga-DOTATATE PET-CT imaging in patients with medullary thyroid cancer

Annals of Nuclear Medicine ◽

10.1007/s12149-020-01494-3 ◽

2020 ◽

Vol 34 (9) ◽

pp. 663-674

Author(s):

Murat Tuncel ◽

Saadettin Kılıçkap ◽

Nilda Süslü

Keyword(s):

Thyroid Cancer ◽

Medullary Thyroid Cancer ◽

Ct Imaging ◽

Clinical Impact ◽

Medullary Thyroid ◽

Pet Ct

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Tc-99m HYNIC-TOC scintigraphy in dedifferentiated thyroid cancer

BMJ Case Reports ◽

10.1136/bcr-2018-227910 ◽

2019 ◽

Vol 12 (4) ◽

pp. e227910

Author(s):

Kanhaiyalal Agrawal ◽

P Sai Sradha Patro ◽

C Preetam

Keyword(s):

Thyroid Cancer ◽

Single Photon ◽

Somatostatin Receptor ◽

Photon Emission ◽

Peptide Receptor Radionuclide Therapy ◽

Ct Imaging ◽

Whole Body ◽

Emission Computed Tomography ◽

Serum Thyroglobulin ◽

Pet Ct

There is literature evidence showing utility of somatostatin receptor (SSTR) positron emission tomography-CT (PET-CT) imaging in differentiated thyroid cancer with Thyroglobulin Elevated and Negative Iodine Scan (TENIS). These patients are less benefited with I-131 therapy and surgery remains only curable option if disease could be localised. If surgery is not feasible, other therapeutic options are not promising. However, if these patients show strongly positive SSTR imaging, then possibility of peptide receptor radionuclide therapy may be explored. As SSTR PET-CT imaging is expensive and not widely available, Technetium-99m (Tc-99m) hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC), which is a Single photon emission computed tomography (SPECT) tracer, can be used. We are documenting a case of raised serum thyroglobulin antibody and negative I-131 whole body scan with disease recurrence localised on Tc-99m HYNIC-TOC scan.

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Salivary gland protection by amifostine in high-dose radioiodine treatment: results of a double-blind placebo-controlled study.

Journal of Clinical Oncology ◽

10.1200/jco.1998.16.11.3542 ◽

1998 ◽

Vol 16 (11) ◽

pp. 3542-3549 ◽

Cited By ~ 61

Author(s):

K H Bohuslavizki ◽

S Klutmann ◽

W Brenner ◽

J Mester ◽

E Henze ◽

...

Keyword(s):

Thyroid Cancer ◽

Salivary Gland ◽

Salivary Glands ◽

Differentiated Thyroid Cancer ◽

Controlled Study ◽

High Dose ◽

Radioiodine Treatment ◽

Double Blind ◽

Double Blind Placebo ◽

Submandibular Glands

PURPOSE Salivary gland impairment is a well-recognized side effect following high-dose radioiodine treatment (HD-RIT). Since differentiated thyroid cancer has a good prognosis, reduction of long-term side effects is important. Therefore, the effect of amifostine was studied in HD-RIT. PATIENTS AND METHODS Parenchymal function was assessed by quantitative salivary gland scintigraphy performed prospectively in 50 patients with differentiated thyroid cancer before and 3 months after HD-RIT with either 3 GBq iodine ((131)I) (n=21) or 6 GBq (131)I (n=29) in a double-blind, placebo-controlled study. Twenty-five patients were treated with 500 mg/m2 amifostine intravenously before HD-RIT and 25 patients served as controls, who received physiologic saline solution. Xerostomia was graded according to World Health Organization (WHO) criteria. RESULTS Before HD-RIT in 25 control patients, uptake of technetium-99m (99mTc)-pertechnetate was 0.45%+/-0.16% and 0.42%+/-0.16% in parotid and submandibular glands, respectively. Three months after HD-RIT, parenchymal function was significantly (P < .001) reduced by 40.2%+/-14.1% and 39.9%+/-15.3% in parotid and submandibular glands, respectively. Nine control patients developed grade I and two grade II xerostomia. In 25 amifostine-treated patients, uptake of 99mTc-pertechnetate was 0.46%+/-0.16% and 0.43%+/-0.17% in parotid and submandibular glands, respectively. Three months after HD-RIT, parenchymal function of salivary glands was not significantly altered (P=.691) and xerostomia did not occur in any of these patients. CONCLUSION Parenchymal damage in salivary glands caused by HD-RIT can significantly be reduced by amifostine, which may improve the quality of life of patients with differentiated thyroid cancer.

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